I think you’re a clever fellow. I just see one small flaw in your post. Are you sure that the proportion of homosexual was so low as you suggested during the exponential phase of humanity demography? I guess no.
Sylas’s remark is fine. Because of the personality high diversity, homosexual behaviours are likely to appear. As far as I know, an individual becoming homosexual is randomised within a population. The social environment plays a crucial regulation role in the development of this behaviour. I don’t think genetic or “black-boxed” hidden mechanisms are to blame for this.
I can speak only for my self based on the logic of my personal vision, but I consider a strong relation between AIDS menace and female homosexuality. If you fancy it, this is a psychological response to harsh social condition. In term of safety, indeed.
I still believe that attraction for same sex is hormone mediated. Visual stimulis are hightly efficient either for sex and phobia. IOW the reaction is immediate.
I believe that in dense population, such stimulis could be highjacked because of saturation. This perturbation of the "natural" mechanism of opposit sex recognition, could induce "wrong" attraction target here and here.
Just an idea (perhaps off topic): When proposing assortment of factors, do you think that pheromones could be involved?
Thank Custard you for this very good compilation paper. There are indeed many interesting data in it. Mine are scattered and statistics certainly non realistic on general case.
But I think it's fine to point again the sad position of religions against lesbian (& Gay) people because of the cornerstone of the problem comes from them. Honestly, my preference is now governed by my heart, not by the holy doctrines. A small personal victorious fact, but lovely to appreciate each days. Sin motivated lol!